1. Field of the Invention
The present invention relates to an image data enlarging/reducing function, and more particularly to an image data enlarging/reducing apparatus preventing increases of circuit scale and development cost.
2. Description of the Background Art
In recent years, information processing equipment such as a personal computer has been widespread. One of the functions of such information processing equipment is an enlarging/reducing function of image data. Japanese Patent Laying-Open No. 6-215123 discloses a technique related thereto.
The image editing device disclosed in Japanese Patent Laying-Open No. 6-215123 enlarges/reduces an image in a horizontal direction. Upon enlargement, it reads the same line or column a plurality of times, while it skips an unnecessary line or column upon reduction. It performs data transfer collectively in a unit of block by direct memory access (DMA).
Conventionally, rapid enlargement/reduction of image data required a circuit dedicated to image data processing. Adding such a function of rapidly enlarging/reducing image data would increase the circuit scale and/or the development cost of the information processing equipment.
Further, although Japanese Patent Laying-Open No. 6-215123 described above is related to the image data enlarging/reducing technique, enlargement/reduction of the image is conducted solely in the horizontal direction. It does not disclose a technique for enlarging/reducing the image in a vertical direction.